/*
 * Copyright (c) 2007-2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: FunctionPattern.java,v 1.2.4.2 2005/09/15 00:21:15 jeffsuttor Exp $
 */
package com.sun.org.apache.xpath.internal.patterns;

import com.sun.org.apache.xml.internal.dtm.DTM;
import com.sun.org.apache.xml.internal.dtm.DTMIterator;
import com.sun.org.apache.xpath.internal.Expression;
import com.sun.org.apache.xpath.internal.ExpressionOwner;
import com.sun.org.apache.xpath.internal.XPathContext;
import com.sun.org.apache.xpath.internal.XPathVisitor;
import com.sun.org.apache.xpath.internal.objects.XNumber;
import com.sun.org.apache.xpath.internal.objects.XObject;

/**
 * Match pattern step that contains a function.
 * @xsl.usage advanced
 */
public class FunctionPattern extends StepPattern {
    static final long serialVersionUID = -5426793413091209944L;

    /**
     * Construct a FunctionPattern from a
     * {@link com.sun.org.apache.xpath.internal.functions.Function expression}.
     *
     * NEEDSDOC @param expr
     */
    public FunctionPattern(Expression expr, int axis, int predaxis) {

        super(0, null, null, axis, predaxis);

        m_functionExpr = expr;
    }

    /**
     * Static calc of match score.
     */
    public final void calcScore() {

        m_score = SCORE_OTHER;

        if (null == m_targetString)
            calcTargetString();
    }

    /**
     * Should be a {@link com.sun.org.apache.xpath.internal.functions.Function expression}.
     *  @serial
     */
    Expression m_functionExpr;

    /**
     * This function is used to fixup variables from QNames to stack frame
     * indexes at stylesheet build time.
     * @param vars List of QNames that correspond to variables.  This list
     * should be searched backwards for the first qualified name that
     * corresponds to the variable reference qname.  The position of the
     * QName in the vector from the start of the vector will be its position
     * in the stack frame (but variables above the globalsTop value will need
     * to be offset to the current stack frame).
     */
    public void fixupVariables(java.util.Vector vars, int globalsSize) {
        super.fixupVariables(vars, globalsSize);
        m_functionExpr.fixupVariables(vars, globalsSize);
    }

    /**
     * Test a node to see if it matches the given node test.
     *
     * @param xctxt XPath runtime context.
     *
     * @return {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NODETEST},
     *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NONE},
     *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NSWILD},
     *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_QNAME}, or
     *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_OTHER}.
     *
     * @throws javax.xml.transform.TransformerException
     */
    public XObject execute(XPathContext xctxt, int context) throws javax.xml.transform.TransformerException {

        DTMIterator nl = m_functionExpr.asIterator(xctxt, context);
        XNumber score = SCORE_NONE;

        if (null != nl) {
            int n;

            while (DTM.NULL != (n = nl.nextNode())) {
                score = (n == context) ? SCORE_OTHER : SCORE_NONE;

                if (score == SCORE_OTHER) {
                    context = n;

                    break;
                }
            }

            // nl.detach();
        }
        nl.detach();

        return score;
    }

    /**
     * Test a node to see if it matches the given node test.
     *
     * @param xctxt XPath runtime context.
     *
     * @return {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NODETEST},
     *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NONE},
     *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NSWILD},
     *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_QNAME}, or
     *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_OTHER}.
     *
     * @throws javax.xml.transform.TransformerException
     */
    public XObject execute(XPathContext xctxt, int context, DTM dtm, int expType) throws javax.xml.transform.TransformerException {

        DTMIterator nl = m_functionExpr.asIterator(xctxt, context);
        XNumber score = SCORE_NONE;

        if (null != nl) {
            int n;

            while (DTM.NULL != (n = nl.nextNode())) {
                score = (n == context) ? SCORE_OTHER : SCORE_NONE;

                if (score == SCORE_OTHER) {
                    context = n;

                    break;
                }
            }

            nl.detach();
        }

        return score;
    }

    /**
     * Test a node to see if it matches the given node test.
     *
     * @param xctxt XPath runtime context.
     *
     * @return {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NODETEST},
     *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NONE},
     *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NSWILD},
     *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_QNAME}, or
     *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_OTHER}.
     *
     * @throws javax.xml.transform.TransformerException
     */
    public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException {

        int context = xctxt.getCurrentNode();
        DTMIterator nl = m_functionExpr.asIterator(xctxt, context);
        XNumber score = SCORE_NONE;

        if (null != nl) {
            int n;

            while (DTM.NULL != (n = nl.nextNode())) {
                score = (n == context) ? SCORE_OTHER : SCORE_NONE;

                if (score == SCORE_OTHER) {
                    context = n;

                    break;
                }
            }

            nl.detach();
        }

        return score;
    }

    class FunctionOwner implements ExpressionOwner {
        /**
         * @see ExpressionOwner#getExpression()
         */
        public Expression getExpression() {
            return m_functionExpr;
        }

        /**
         * @see ExpressionOwner#setExpression(Expression)
         */
        public void setExpression(Expression exp) {
            exp.exprSetParent(FunctionPattern.this);
            m_functionExpr = exp;
        }
    }

    /**
     * Call the visitor for the function.
     */
    protected void callSubtreeVisitors(XPathVisitor visitor) {
        m_functionExpr.callVisitors(new FunctionOwner(), visitor);
        super.callSubtreeVisitors(visitor);
    }

}
